In 2009, Rudd again appeared with Jason Segel in I Love You Man where he and Segel play buddies who bond over their shared love for the rock band Rush. Both Rudd and Segel are themselves fans of the band.[31][32] Also in 2009, Rudd co-created the TV series Party Down with John Embom, Rob Thomas and Dan Etheridge.[26] He lent his voice to the DreamWorks computer-animated hit movie Monsters Vs. Aliens.

In 2012, Rudd appeared in the Broadway production of Craig Wright's Grace. The play was performed at the Cort Theatre. Starring alongside Rudd was Academy award nominee Michael Shannon, Kate Arrington, and seven-time Emmy award winner Ed Asner. The play was first acclaimed at the Woolly Mammoth Theatre in Washington, D.C. In 2004. It would then go on to receive equal praise at NorthLight Theatre in Chicago and then at the Pasadena Playhouse in LA, where it received three L.A. Drama Critics Circle Awards, including Best Play.

Rudd received a star on the Hollywood Walk of Fame on July 1, 2015. He unveiled the 2,554th star on the mile-long strip of plaques on Hollywood Boulevard. At the occasion Rudd said, "I remember being a kid and walking this boulevard and reading the names and thinking about what so many other millions of people thought about, which is, you know, 'Who's that?'"[50]

Rudd is a supporter of the Stuttering Association for the Young (SAY), a nonprofit organization to help young people who stutter. He hosted the organization's 6th Annual All-Star Bowling Benefit on January 22, 2018.[51] Rudd told Vanity Fair that he became an advocate for stuttering awareness after portraying a character who stutters in a play.[52]